This invention relates to magnetic imaging, and more particularly to a magnetic scanner-recorder for optical helical scanning of a document with the scanner interfaced with magnetic helical writing through electronic circuitry.
The recordation of magnetic signals upon a magnetizable member such as magnetic tape is known. Recorded magnetic signals are used extensively in audio tape recordings, in magnetic video recording as indicated in U.S. Pat. Nos. 3,108,281 and 3,862,355.
To obtain faster recording, it was found desirable to move the magnetic recording head and magnetizable medium relative to one another both circumferentially and axially during the writing process, as disclosed in U.S. Pat. No. 2,850,348 for magnetic drum printing and as shown in U.S. Pat. No. 3,845,500 for a rotating magnetic head about which a magnetic tape is helically wrapped during its path of travel.
The magnetic reproduction of hard copy original images has theretofore been limited substantially to rather cumbersome techniques involving intermediates such as the use of an optical mask for thermoremanent or Curie-point imaging; or, the use of a xerographically formed intermediate image which is magnetized and used as a master for either direct development with magnetic toner or for transfer of its pattern of magnetization to a magnetic tape via Curie-point techniques. Alternatively, rather cumbersome techniques requiring the mounting of an original image onto a rotating mandral such as is shown in U.S. Pat. No. 2,826,634 have been required.